1. Field of the Invention
The present invention relates to a wireless sensor-actor network (WSAN), and particularly to a WSAN simultaneous failures recovery method.
2. Description of the Related Art
Wireless Sensor and Actor Networks (WSANs) have attracted a lot of interest in recent years. Their potential applications include search-and-rescue, forest fire detection and containment, battlefield reconnaissance, under-water surveillance, etc. In a WSAN, the area of interest is densely-populated with miniaturized battery-operated sensor nodes that are to probe their surroundings and send the collected data to more capable actor nodes for processing and putting forward an appropriate response.
For example, sensors can detect rising temperatures in some spots in a forest and inform mobile robots (actors) that correlate the sensors reports and conclude that the rising temperatures are caused by the outbreak of a fire. The robots would then coordinate among themselves to plan a response that may include moving to the affected location and spraying chemicals to extinguish the fire. Given the collaborative nature of the WSAN operation, inter-actor connectivity is essential. Obviously, coordination among actors cannot be performed in a partitioned network topology. Therefore, actors strive to sustain communication links among each other when they move.
However, the failure of one or multiple actors may partition the network into disjoint sub-networks. This may happen while responding to a harsh event, e.g., a fire, and would require a rapid recovery so that the event would not get out of hand and lead to disastrous consequences. Since WSANs operate unattended and the deployment of spare actors may take time, the recovery should be performed through network self-reconfiguration using existing resources. Recently, this problem has received a lot of attention, and multiple recovery solutions are proposed. However, these approaches are restricted to one failure at a time and do not handle simultaneous failures.
Thus, a WSAN simultaneous failures recovery method solving the aforementioned problems is desired.